(CNN) — New data has found women tend to report more adverse side effects to the COVID-19 vaccine than men.
A new report from the CDC and the FDA found that 13 million doses of the vaccine were administered from mid-December through mid-January.
Of those, nearly 7,000 adverse side effects like headaches and fatigue were report. The CDC says about 79% of those side effects were reported by women.
A CDC researcher says that could be because more women received the vaccine, but it says it could also be biological.
The researcher says studies suggest women have higher anti-body responses than men to certain vaccines, like influences.